Slack take-up and brake-release mechanism



Dec. .8, 1925- 1,564,445

0. H. READ SLACK TAKE-UP AND BRAKE RELEASE MECHANISM Filed June 15. 1922INVENTOR ATTORN EY Patented Dec. 8, 1925..

PATENT QFFICE.

CHARLES H. HEAD, OF PITTSBURGH, PENNSYLVANIA.

SLACK TAKE-U]? AND BRAKE-RELEASE MECHANI$1L Application filed June 15,1922.

To all whom it may concern:

Be it known that 1, CHARLES H. READ, a citizen of the United States,residing at Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in SlackTake-Up and Brake-Release Mechanism, of which im provement the followingis a specification.

My invention relates to improvements in the foundation brake rigging ofrailway vehicles. The ob ects of the lnvention are to produce anapparatus of this kind in which the traverse or movement of the leversin applying the brakes is increased without increasing the presentnormal travel of the piston with a consequent conservation in airpressure and a quicker brake application than is possible with theapparatus now in use and in which a quick and positive brakeshoe releaseis obtained.

I accomplish these objects by means of the apparatus hereinafter morefully described, which broadly stated comprises two sets or systems oflevers designated herein as the primary set and the secondarv set, andrela tively occupying the same vertical plane. The secondary set beingoperated by and deriving its power from the primary set and acting oroperating simultaneously with the primary set or system and in the samedirection and in such manner as to increase or enlarge the scope oraction of the primary system without increasing the present normalpiston travel. The said apparatus or device is hereinafter more fullydescribed, reference being had to the accompanying drawings forming parthereof, in which:

Fig. l is a diagrammatic plan View of the air brake cylinder, its leversand the slack adjustment and brake-shoe release.

Fig. 2 is a conventional diagrammatic view of the ordinary foundationbrake rigging, the structure being shown in plan except the wheels,which are shown in elevation.

Referring to said drawings: 1 is an air brake cylinder, 2 and 3 arerespectively the operating levers, herein called the primary levers, ormore commonly called the live and dead levers, and which for convenienceI will herein call the live and dead levers respectively; the said livelever is pivotally connected to and directly operated by the piston rod4, which is operatively seated in said cylinder, the said dead lever 3,being Serial No. 568,473.

pivotally connected to a stationary point, or as shown in the drawings,to the end of the cylinder opposite the live lever 2. A connectingelement comprising two independent connecting rods 5 and 5 is interposedbetween said levers, the main or longest section 5 being connected atone end to the dead lever, and the opposite end pivotally to a lever 6,herein called the secondary lever, which is disposed between saidprimary levers 2 and 3; the section 5 of said connecting element isconnected at one end to the live lever and at the opposite end to saidlever 6 at or near the outer end thereof. an auxiliary connecting rod 7is connected at one end to the live lever at a point between the shortconnecting rod 5 and the pivotal point of connection between the pistonandthe live lever 2, and at the opposite end with the lever 6 at or nearthe inner end thereof. 8 is a rod connected to the lever 6 at or nearthe end thereof, the opposite end of said rod being connected to a plate9, between which and the plate 10 a compressive spring 11 is operativelymounted on the link or clevis 12, to one end of which the said plate 10is connected, the opposite end of said link or clevis being connected toa rod 13 which is pivotally connected to the dead lever. The said plates9 and 10 are slidably mounted on said link whereby when a brakeapplication is made the movement of the piston carries the live leverforward, which in turn carries the inner end of the secondary lever 6forward, thereby compressing said spring, the retraction of which uponthe release of air pres sure produce a quick and positive release cf thebrake-shoes.

The operation of the device is as follows: In order to make a brakeapplication, the piston of the cylinder is caused to move in the usualmanner, carrying the live lever connected to the outer end of saidpiston into the position shown by dotted lines, and through the agencyof the connecting element, the dead lever is brought into the positionshown by the dotted lines. The outer ends of said levers, which fromtheir func tion I define as the primary levers, being, as shown, movedinward or toward each other, applying the brake-shoes in the usualmanner. It will be noted that the adjacent ends of the two independentrods 5 and 5, which constitute the connecting element which is pivotallysecured to the lever 6, disposed between the operating levers 2 and 3are compelled to move in opposite direction during brake application,the end oi? the short section moving toward the dead lever and the endof the long section mow ing toward the live lever, thus shortening thecombined length of the two sections and carrying the outer end of thetwo operat ing levers 2 and 3, herein called the dead and live levers,closer together with a short er running travel of the piston rod thancan be obtained in the operation of the f0undation rigging now in use,in which the corn necting rod is formed of a single continuous element.The effect 01. this diiierence is that the brakes can be applied in ashorter period of time with a shorter running travel of the piston and aconsequent saving of brake pressure and consumption of air. Themovement; of the piston operating le vers 2 and 3 in a brake applicationcompresses the spring, as heretofore herein described, and as a matterof course utilizes a portion of the cylinder air pressure in so doing,the comparatively short running travel oi? the piston, however, lessensair pressure reduction in the cvlinder and the gain in this respect moretnan compensates for the power used in compressing the spring. hen thebrakes are released in the usual manner, the retraction of the springquickly and positively releases the brake-shoes from the wheels anddraws back the entire rigging and places the apparatus in full releaseposition.

In Fig. 2, I show a conventional diagrammatic view of the ordinaryfoundation brake rigging, in which a continuous one piece connecting rodis used. As this construction is well known, a brief statement of theparts will sufiice; a is the brake cylinder; 1) and c are respectivelythe live and dead levers; Z is the connecting rod connecting saidlevers, the lower end of said levers being con uectcd with thebrake-shoe levers.

I do not wish or intend to limit myself to any particular mechanicalmeans of producing the simultaneous augmentation of the action of thelevers, as it is obvious that other mechanical means may be so employed;my intention being, however, to cover broadly the dual action of theprin'iary and secondary system of levers, one of which, the secondarysystem, derives its power from the primary system and augments themovement or action of the primary system in a brake application.

The slack which itis necessary to at just or take up, arises from wearof pins and holes, wear of brasses, loose boXes in pedestals, etc., andit is provided for in the ordinary brake foundation rigging by incrising the travel of the piston, but as now arranged this increasedpiston travel leads to a loss 01" air pressure in the brake cylinder,greater consumption of air, slower brake application, etc. The presentinvention meets and remedies these disadvantages by shortening thepiston travel, while increasing the travel of the entire rigging.

It will be noted that heretofore the slack was taken up and heldpositively and permanently until released by some other action andthrough some other instrumentality than the brake release. In thepresent invention the slack is taken up and upon release of the brakesautomatically assumes its normal condition.

Havii'ig described my invention, what 1 claim and desire to secure byLetters Patent is:

1. A slack take up and brake release mechanism for railway vehicles,comprising a plurality of sets of levers, including a primary set and asecondary set in the same vertical plane, and means cooperating withsaid levers for automatically releasing the slack at each brake release.

A slack take up and brake release mechanism for railway vehiclescomprising an actuating set or levers and an actuated set of levers andmeans cooperating with said actuated set adapted to increase themovement of the actuating set without increasing the travel of thepiston.

3. A slack take up and brake release mechanism for railway vehiclescomprising primary and secondary systems of levers and an elementconnecting said systems including a divided rod, the secondary set oflevers being adapted on brake application to shorten said connecting rodand to lengthen the same on brake release.

l. A slack take up and brake release mechanism for railway vehicles,comprising a plurality of sets of levers, includii'ig an actuating setand an actuated set and means interposed between said sets of levers andcooperating with the actuating set of lovers to simultaneously operateboth sets in the same direction and increase the movement of theactuating set without in-- creasing the travel of the piston.

A slack take up and brake release mechanism for railway vehicles,comprising a primary and a secondary set of levers, a connecting elementdivided into two parts, the said parts being arranged ondifferenthorizontal planes.

- 6. In the foundation brake rigging of railway vehicles, a connectingelement comprising a plurality of rods, the adjacent ends of which arepivotally secured upon a common support disposed between the live anddead levers.

T. In the foundation brake rigging of railway vehicles, a lever disposedbetween the operating levers and a connecting elerent comprising aplu'ality of rods, the

titl

inner ends of which are pivotally secured to said lever, and the outerends respectively to the live and dead levers respectively.

8. In the foundation brake rigging of railway vehicles, the combinationof an air pressure cylinder, a piston operable therein, a dead leverpivotally connected to one end of said cylinder, a live lever connectedto the piston of said cylinder, a connecting rod comprising twoindependent sections, a lever disposed between the dead and live levers,the inner end of the short section of said connecting rod beingconnected to one end of said lever and at the opposite end to the livelever, the inner end of the main section of said connecting rod beingconnected to said lever and the opposite end to the dead lever.

9. In a slack take up and brake release mechanism comprising a pluralityof sets of levers, a connecting rod interposed between said leversformed in two sections, the said sections being so arranged that onbrake application their combined length between said levers is shortenedand their combined length being limited to the original distance betweensaid levers when the apparatus is in released position.

10. In the foundation brake rigging of 'ailway vehicles, the combinationof slack take up and brake-shoe release mechanism, including aconnecting rod formed in tWo sections, a lever disposed between theextrerne outer ends of said sections, the inner ends of both of saidsections being pivotally secured upon said lever and the outer ends ofsaid sections being ipivotally secured to the dead and live leversrespectively, in combination with means to quickly and positivelyrelease the brake-shoes upon the release of brake pressure.

' 11. In the foundation brake rigging of railway vehicles,thecombination of abrake cylinder, operating levers, the inner end ofone of which is'pivotally secured to the piston of said cylinder and thecorresponding end of the other is pivotally secured to a stationarypoint at the opposite end of said cylinder, slack take up and brakerelease mechanism including a connecting rod formed in two sections, alever interposed between the operating levers, the inner ends of both ofsaid sections of said connecting element being pivotally secured to saidlever and the opposite ends of said sections being pivotally secured tothe operating levers respectively, an auxiliary connecting rod pivotallysecured to the lever connected to the piston and at the opposite end tosaid lever, and a compressive spring mounted between the inner end ofsaid lever and the dead lever.

In testimony whereof, I have hereunto signed my name.

CHARLES H. READ.

